Vacuum frames employed for supporting a superimposed original and copy sheet have long been used for maintaining the sheets in close contact during exposure to light in order to achieve the best possible contact copy. Vacuum frames of this kind consist of a base that supports a backing or blanket upon which the copies are placed and an upper frame member including a glass plate to permit exposure of the sheets to light. While vacuum frames of this kind have been widely used, as air is removed, the backing or blanket tends to rise toward the glass in an unpredictable pattern. This causes air pockets to become trapped between the sheets or between the glass and the superimposed sheets. Several minutes may be required before these trapped air pockets or air bubbles finally work their way out of the system so that the exposure can be made. Moreover, it has been common for exposures to be wasted due to the presence of trapped air pockets. Because both setup time and materials are costly, previous vacuum frame systems have been wasteful and unnecessarily expensive to operate. Previous efforts to eliminate these problems have been unsuccessful.